CN206379620U - A kind of generation device of 2.1 micron waveband pulse laser - Google Patents

Abstract

The utility model is applicable to the field of optics, and provides a 2.1-micron band pulse laser generating device, including a semiconductor pump pulse laser, a pump light focusing coupling system, and a resonant cavity. The resonant cavity includes an end-pumped laser medium. The end-pumped laser medium is a vanadate crystal doped with neodymium ions; the pump light generated by the semiconductor pump pulse laser is coupled into the vanadate crystal doped with neodymium ions through the pump light focusing coupling system Crystal, neodymium ions generate 1.34 micron band pulsed laser through stimulated radiation, and the 1.34 micron band pulsed laser oscillates in the resonant cavity; the vanadate crystal performs Raman frequency conversion three times on the 1.34 micron band pulsed laser Function and film-locking function, output 2.1 micron band pulsed laser. The 2.1 micron band pulsed laser generator provided by the utility model avoids the limitation of a saturable absorber with a lower light damage threshold, and obtains a high-power, high-energy 2.1 micron band pulsed laser.

Description

A device for generating pulsed laser in the 2.1 micron band

technical field

The utility model belongs to the optical field, in particular to a 2.1-micron band pulse laser generator.

Background technique

At present, there are two main ways to obtain pulsed laser in the 2.1 μm band: 1. Solid-state or fiber-optic pulsed laser with trivalent rare earth elements Tm ³⁺ and Ho ³⁺ as active ions. 2. The optical parametric oscillator (OPO) of ZnGeP (ZGP) or KTiOPO ₄ (KTP) crystal is pumped by 1 μm band pulsed laser. The second acquisition method is rarely used due to the complex structure, high cost and low efficiency of the devices used.

The technologies for generating ultrashort pulse lasers in the 2.1 μm band are mainly divided into active mode-locking and passive mode-locking. Active mode-locking requires a relatively long response time of the modulation element, and the resulting loss window is very wide, so the obtained pulse width is relatively wide, usually on the order of tens to hundreds of picoseconds (ps). Passive mode-locking utilizes the fast response time of saturable absorbers to obtain ultrashort pulse lasers as short as femtoseconds (fs). At present, the saturable absorbers in the 2.1μm band mainly include: (1) Absorbing crystals, such as: PbS quantum dot glass, Cr ²⁺ : ZnS, Cr ²⁺ : ZnSe, etc.; (2) Semiconductor materials: such as semiconductor saturable absorbing mirrors (SESAM), InGaAs, etc.; (3) New one-dimensional and _two -dimensional materials, such as graphene, carbon nanotubes, MoS2, etc. However, the low optical damage threshold of saturable absorbers limits the output power of passively mode-locked ultrashort pulse lasers in the 2.1 μm band.

Therefore, there are defects in the prior art and need to be improved.

Utility model content

In order to solve the above-mentioned technical problems, the utility model provides a 2.1-micron band pulse laser generating device, aiming at obtaining high-power, high-energy 2.1-micron-band ultrashort pulse laser while simplifying the production process.

The utility model provides a 2.1 micron band pulsed laser generating device, comprising a semiconductor pumped pulsed laser, a pump light focusing coupling system and a resonant cavity, the resonant cavity includes an end-pumped laser medium, and the end-pumped laser The medium is a vanadate crystal doped with neodymium ions; the pump light generated by the semiconductor pump pulse laser is coupled into the vanadate crystal doped with neodymium ions through the pump light focusing coupling system, and the neodymium ions pass through Stimulated radiation to generate a 1.34-micron-band pulsed laser, the 1.34-micron-band pulsed laser oscillates in the resonator; the vanadate crystal performs Raman frequency conversion and mode-locking on the 1.34-micron-band pulsed laser, Generate a 1.52-micron-band pulsed laser, and the 1.52-micron-band pulsed laser oscillates in the resonant cavity; the vanadate crystal performs Raman frequency conversion and mode-locking on the 1.52-micron-band pulsed laser to generate a 1.76-micron Band pulsed laser, the 1.76 micron band pulsed laser oscillates in the resonant cavity; the vanadate crystal performs Raman frequency conversion and mode locking on the 1.76 micron band pulsed laser, and outputs 2.1 micron band pulsed laser.

Further, the resonant cavity also includes a pump end cavity mirror, and the pump end cavity mirror is located between the pump light focusing coupling system and the end pump laser medium, and is used to reflect 1.34 micron, 1.52 micron , 1.76-micron and 2.1-micron pulsed lasers, and simultaneously transmit pump light in the 808-nm band.

Further, the resonant cavity also includes an output mirror, which is used to reflect the pulsed laser light in the 1.34 micron, 1.52 micron and 1.76 micron bands, and simultaneously reflect and transmit the 2.1 micron band.

Further, the resonant cavity further includes an acousto-optic Q switch, and the acousto-optic Q switch is located between the end-pumped laser medium and the output mirror, and is used to increase the pulsed laser power density in the resonant cavity.

Further, the wavelength of the pump light is 808 nanometers.

Further, the end-pumped laser medium is Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal.

Compared with the prior art, the utility model has the beneficial effect that: the utility model provides a 2.1 micron band pulsed laser generating device, the resonant cavity of the generating device includes an end-pumped laser medium, and the end-pumped laser The medium is a vanadate crystal doped with neodymium ions; first, stimulated radiation is generated by neodymium ions to generate a 1.34-micron-band pulsed laser, and then the 1.34-micron-band pulsed laser is used as the fundamental frequency light, using the three-time Raman frequency conversion of the vanadate crystal Function and mode-locking function, output 2.1 micron band pulsed laser. The utility model combines the excellent self-Raman frequency conversion characteristic of the vanadate crystal doped with neodymium ions and the mode-locking characteristic of the Kerr lens, through three modes of Kerr lens mode-locking, saturated Raman gain and synchronous pumping The mechanism produces stable mode-locking of the 2.1 μm band pulse laser, and finally outputs the ultrashort pulse laser of the 2.1 μm band. The 2.1 micron band pulse laser generating device provided by the utility model can obtain high-power, high-energy ultrashort pulse laser in the 2.1 micron band because it avoids the limitation of a saturable absorber with a lower optical damage threshold.

Description of drawings

Fig. 1 is a schematic structural diagram of a 2.1 micron band pulsed laser generating device provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

As shown in Figure 1, the utility model embodiment provides a kind of 2.1 micron band pulsed laser generating device 100, comprises semiconductor pump pulse laser (not shown), pumping light focusing coupling system 2 and resonant cavity 7, resonant The cavity 7 includes an end-pumped laser medium 4; wherein, 1 is an optical fiber output end of a semiconductor pump pulse laser, and the end-pump laser medium 4 is a vanadate crystal doped with neodymium ions; the pump generated by the semiconductor pump pulse laser The light is coupled into the vanadate crystal (end-pumped laser medium 4) doped with neodymium ions through the pump light focusing coupling system 2, and the neodymium ions generate 1.34 micron band pulsed laser through stimulated radiation, and the 1.34 micron band pulsed laser Oscillating in the resonant cavity 7; the vanadate crystal performs Raman frequency conversion and mode locking on the 1.34 micron band pulsed laser to generate a 1.52 micron band pulsed laser, and the 1.52 micron band pulsed laser is in the resonant cavity 7 Oscillation; the vanadate crystal performs Raman frequency conversion and mode-locking on the 1.52 micron band pulsed laser to generate a 1.76 micron band pulsed laser, and the 1.76 micron band pulsed laser oscillates in the resonant cavity 7; The vanadate crystal performs Raman frequency conversion and mode locking on the 1.76 micron band pulsed laser, and outputs a 2.1 micron band pulsed laser.

Specifically, the 1.34-micron-band pulsed laser generates a 2.1-micron-band pulsed laser under the self-Raman frequency conversion effect of the vanadate crystal and the mode-locking effect of the Kerr lens.

Specifically, the wavelength of the pump light is 808 nanometers.

The resonant cavity 7 also includes a pump end cavity mirror 3, which is located between the pump light focusing coupling system 2 and the end pump laser medium 4, and is used to reflect 1.34 microns, 1.52 microns, 1.76 microns and 2.1 microns The pulsed laser in the wavelength band and the pump light in the 808 nanometer band are transmitted simultaneously.

The resonant cavity 7 also includes an output mirror 6, which is used to reflect the pulsed laser light in the 1.34 micron, 1.52 micron and 1.76 micron bands, and simultaneously reflect and transmit the 2.1 micron band.

Specifically, the cavity mirror 3 at the pump end can be a plane mirror, a plano-convex mirror or a plano-concave mirror, coated with a dielectric film that is highly transparent to 808nm-band pulsed lasers and highly reflective to 1.34-micron, 1.52-micron, 1.76-micron and 2.1-micron-band pulsed lasers The output mirror 6 can be a plane mirror, a plano-convex mirror or a plano-concave mirror, coated with a dielectric film that is highly reflective to 1.34 micron, 1.52 micron and 1.76 micron band pulsed lasers and partially reflective and partially transparent to 2.1 μm band pulsed lasers.

The resonant cavity 7 also includes an acousto-optic Q switch 5 , which is located between the end-pumped laser medium 4 and the output mirror 6 to increase the pulsed laser power density in the resonant cavity 7 .

Specifically, the end-pumped laser medium 4 can be Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal, and Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal uses pulsed laser light in the 1.34 μm band as the fundamental frequency light, using vanadate The three-time Raman frequency conversion and mode-locking effect of the crystal around 890cm ^-1 produces 2.1μm-band pulsed laser light.

The 2.1 micron band pulsed laser generating device provided in this embodiment combines the 890 cm ^-1 Raman frequency conversion characteristic of the vanadate crystal doped with neodymium ions and the mode-locking characteristic of the Kerr lens, specifically through the Kerr lens The three mechanisms of mode-locking, saturated Raman gain and synchronous pumping produce stable mode-locking of 2.1μm-band pulsed lasers, thus obtaining high-power, high-energy 2.1μm-band ultrashort pulsed lasers.

This embodiment also provides a method for generating a 2.1 micron-band pulsed laser, comprising the following steps:

S1: The pump light generated by the semiconductor pump pulse laser is coupled into the vanadate crystal doped with neodymium ions through the pump light focusing coupling system, and the neodymium ions generate pulsed laser light in the 1.34 micron band through stimulated radiation;

S2: Using the pulsed laser in the 1.34 micron band as the fundamental frequency light, using the Raman frequency conversion effect and mode locking effect of the vanadate crystal to generate a pulsed laser in the 1.52 micron band;

S3: Using the Raman frequency conversion effect and mode locking effect of the vanadate crystal, converting the 1.52 micron band pulsed laser into a 1.76 micron band pulsed laser;

S4: Converting the 1.76-micron-band pulsed laser into a 2.1-micron-band pulsed laser by using the Raman frequency conversion and mode-locking effects of the vanadate crystal.

Combined with the above-mentioned 2.1 micron band pulsed laser generating device 100:

Specifically, in step S1, the pump light generated by the semiconductor pump pulse laser is output from the fiber output end 1 of the semiconductor pump pulse laser, and enters the pump light through the pump light focusing coupling system 2, and the pump light focusing coupling system 2 Focusing the pump light on the end-pumped laser medium 4 (vanadate crystal doped with neodymium ions), wherein the neodymium ions generate 1.34-micron-band pulsed laser through stimulated radiation, and the 1.34-micron-band pulsed laser is Oscillation in the resonant cavity 7.

Specifically, in step S2, the vanadate crystal uses the output 1.34 micron band pulse laser as the fundamental frequency light, utilizes the Raman frequency conversion function and mode locking function of the vanadate crystal, and the cavity mirror 3 at the pump end and the output mirror 6 The role of the 1.52 micron band pulsed laser.

Specifically, in step S3, the 1.52-micron-band pulse laser is converted into a 1.76-micron-band pulse by using the Raman frequency conversion and mode-locking effects of the vanadate crystal, as well as the pumping end cavity mirror 3 and the output mirror 6 laser.

Specifically, in step S4, the 1.76-micron-band pulse laser is converted into a 2.1-micron-band pulse by using the Raman frequency conversion and mode-locking effects of the vanadate crystal, as well as the pumping end cavity mirror 3 and the output mirror 6 laser.

Specifically, the wavelength of the pump light is 808 nanometers. The cavity mirror 3 at the pump end can be a plane mirror, a plano-convex mirror or a plano-concave mirror, coated with a dielectric film that is highly transparent to the 808nm band pulsed laser and highly reflective to the 1.34 micron, 1.52 micron, 1.76 micron and 2.1 micron band pulsed laser; the output mirror 6 can be a plane mirror, a plano-convex mirror or a plano-concave mirror, coated with a dielectric film that reflects pulsed lasers in the 1.34 micron, 1.52 micron, and 1.76 micron bands, and at the same time partially reflects and partially transmits the pulsed lasers in the 2.1 micron band. The vanadate crystal doped with neodymium ions may be Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal.

Specifically, the Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal in step S2 uses the 1.34 μm band pulsed laser as the fundamental frequency light, and utilizes the three-time Raman frequency conversion effect and mode locking effect of the vanadate crystal at about 890 cm ^-1 , Produces 2.1μm band pulsed laser light.

The method for generating a 2.1 μm-band pulsed laser provided in this embodiment can obtain high-power, high-energy 2.1 μm-band ultrashort pulse laser because it avoids the limitation of a saturable absorber with a low optical damage threshold.

This embodiment also provides the application of the 2.1 micron band pulsed laser, which has wide and important applications in military, medical, environmental monitoring, material processing, remote communication or metrology and other fields.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (6)

1. A generation device of 2.1 micron wave band pulsed laser, comprising semiconductor pump pulse laser, pump light focusing coupling system and resonant cavity, it is characterized in that, described resonant cavity comprises end-pumped laser medium, and described end-pumped The laser medium is a vanadate crystal doped with neodymium ions; the pump light generated by the semiconductor pump pulse laser is coupled into the vanadate crystal doped with neodymium ions through the pump light focusing coupling system, and the output is 2.1 Pulsed lasers in the micron band. 2. The generating device according to claim 1, wherein the resonant cavity further comprises a pump end cavity mirror, and the pump end cavity mirror is located between the pump light focusing coupling system and the end pump Between the laser media, it is used to reflect the pulsed laser light in the 1.34 micron, 1.52 micron, 1.76 micron and 2.1 micron bands, and at the same time transmit the pump light in the 808 nanometer band. 3 . The generating device according to claim 2 , wherein the resonant cavity further comprises an output mirror for reflecting the pulsed laser light in the 1.34 micron, 1.52 micron and 1.76 micron wavebands, and simultaneously reflecting and transmitting the 2.1 micron waveband. 4. The generating device according to claim 1, wherein the resonant cavity further comprises an acousto-optic Q switch, and the acousto-optic Q switch is located between the end-pumped laser medium and the output mirror, using To increase the pulsed laser power density in the resonant cavity. 5. The generating device according to claim 1, wherein the wavelength of the pumping light is 808 nanometers. 6. The generating device according to claim 1, characterized in that, the end-pumped laser medium is Nd:YVO ₄ crystal or Nd:GdVO ₄ crystal.